January 10, 1992

Whiteflies, Bacteria and Cancer Cells

If a universal antibiotic is found, immediately organize societies to prevent its use. It should be dealt with as we should have treated, and did not treat, the atomic bomb. Use any feasible national and international deterrents to prevent it falling into the hands of stupid people who probably will still be in the majority in your time as they were in mine.

Hilary Koprowski, 1916-

What do whiteflies, bacteria and cancer cells have in common? Plenty! In each case, dealing with them involves an attempt to kill living things chemically: whiteflies with insecticides, bacteria with antibiotics and cancer cells with chemotherapy. The principles that apply to one apply to all.

There are chemicals that will kill all bacteria, all cells and all insects; but many of these agents will kill the cancer patient, the people who eat the crops, or the crops themselves. All of the chemicals that are now in use, are used in doses that will kill mostly what you want them to kill.

It is well established that when you kill cells with a chemical, that it will kill almost all of the cells; say 99.99%. However, an occasional cell or bacterium or insect will mutate and will become resistant to whatever agent is being used. This resistant cell or bug will reproduce until all cells are resistant to the poison being used. At that point the chemical is no longer effective.

Consider the interaction of penicillin and the Staphylococcus(Staph) bacteria which often causes wound infections. Staph is a normal inhabitant of the mouth and skin. For many years, penicillin was very effective against Staph. Even though it was only able to kill most of the bacteria, the normal defenses of the body were able to kill the rest. Eventually, however, strains of Staph developed that were penicillin resistant. These strains were often carried and spread by doctors and nurses. By that time, other antibiotics were developed that attacked the penicillin-resistant staph. There are now a variety of different antibiotics. Eventually, a strain might develop that is resistant to everything that we can throw at it, and we may be back to where we started, with no cures for some bacterial infections.

The same principle applies to the chemotherapy of cancer. As with bacteria, chemicals cannot wipe out all of the cancer cells; just most of them. Consequently, while a person's life can sometimes be prolonged for a long time, chemotherapy rarely cures. There are a few varieties of cancer which the body does attack, and these can be cured with chemicals.

The way that insecticides are used in agriculture is different from the way that antibiotics and chemotherapy are used. Insecticides are used massively and often indiscriminately. As a consequence, a strain of whiteflies has now developed that is resistant to every insecticide known. It is an agricultural disaster. Scientists in agriculture have been predicting this for a long time --it was inevitable. In the process of killing pests, the insects that eat them were also killed. In the past, farmers have been very careful not to kill the bees that pollinate their crops; but they have ignored the predatory insects that eat the pests.

During the attempt to eradicate the Med fly(Mediterranean fruit fly) with malathion, Governor Brown was advised that it wouldn't work; it was not possible to completely eliminate the fly. He was advised correctly, but going against the very powerful chemical industry cost him the governorship. The Med fly is in California to stay. Fruit growers may have to spray their orchards to knock back a heavy infestation, but there is no possible way to eliminate the fly from the state. Those little suckers will be with us forever. The best that can be done is to keep their numbers low enough so that they don't destroy crops.

Insecticides have been a boon to the farmer and to us. The farmers feed the townfolk and every farm that is wiped out by an epidemic of a destructive insect is a disaster. Insecticides are very powerful. Like anything powerful, there is always the potential for harm, by injuring farm workers and by killing necessary beneficial insects. They have to be used very judiciously if we are to gain only the benefits. The utopian idea of a farm without destructive insects is a pipe dream. The best that a farmer can hope for is that the bugs get only a small percentage of his crop.

If everyone was given antibiotics all of the time to prevent disease, it wouldn't be long before all of our antibiotics were ineffective. This almost happened when physicians were giving penicillin for everything. Most have learned not to do that. The present way of using insecticides is a disaster waiting to happen and the whitefly is just the beginning.

Chemotherapeutic agents, antibiotics and insecticides are, like the airplane, wonderful things -but they have to be used very judiciously if the benefits are to outweigh the liabilities. Even the highly touted biological controls could be a two edged sword. It is hard to predict what a new insect or microbe added to the environment will do. There have been several natural disasters brought on by man's attempt to manipulate nature. Things can be improved, but it has to be done very carefully.

There is still no substitute for intelligence, reliable information and experience when dealing with the living world.

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